1. Field of the Invention
The present invention relates to a device for the mechanical treatment of high-consistency fibrous material that may include two treatment tools mounted for relative movement therebetween. The treatment tools may include a plurality of coaxially arranged rows of raised teeth, the rows of teeth for each treatment tool being received in a corresponding space in the other treatment tool. The teeth in each coaxially arranged row may be interconnected by intermediary pieces positioned to form at least a closed gap.
2. Discussion of the Background Information
A treatment device for mechanical treatment of high-consistency fibrous material has been disclosed, for example, in German Patent No. 30 47 013, the disclosure of which is incorporated by reference herein in its entirety. This device, which is suited for dispersing waste paper, is used to intensively process the material in a mechanical and thermal fashion so that unwanted materials contained therein can be removed from the fibers, ground, and/or brought below the limit of visibility. In general, with devices for mechanical treatment of high-consistency fibrous material, the fibrous material is not processed in a suspension that can be pumped, but rather in the form of a doughy or crumbly high-consistency material, preferably with a dry content between 20 and 40%. In this manner, considerably higher shearing forces can be transmitted to the fibrous material, without a significant change in fiber length being correspondingly produced. In many cases, the action of the mechanical treatment is further reinforced by heat, e.g., by setting a fibrous material temperature of 90.degree. C. or higher.
As a result of the high consistency that the fibrous material has during treatment, an intensive mechanical treatment is possible, even though the teeth of the treatment tools that move in relation to one another do not touch, but rather move past one another at a spacing of approx. 1 mm or more. In the process, considerable forces are exerted on the teeth, in particular at the foot of the tooth. Due to lever action, in addition to the shearing forces on the teeth, the tooth foot is engaged by a high moment that rises with increasing tooth height. Further, higher teeth are advantageous since the available through flow cross section is essentially proportional to tooth height. This is why, using one device, a correspondingly greater quantity of material can be treated in the same amount of time with equally high intensity. With larger machining units, a higher economy can almost always be achieved with regard to investment and operational costs.
For prior art devices for mechanical treatment of high-consistency fibrous material, tooth heights that can be achieved in the prior art depend on the manufacturing process. Thus there are cast arcs, which are assembled by being placed against one another into a closed, annular rotor set or stator set. For technical casting and forming reasons, with components of this kind produced for example using the sand is casting process, the gap width and tooth width cannot fall below 6 mm, and the tooth height mostly is not permitted to be more than 30 mm. Devices which are produced in a process of this kind can only have a comparatively low material hardness. The other working process is based on closed individual rings into which the gaps must be milled. These rings are assembled in concentric disposition into a complete rotor set or stator set. Because of the milling process, the gaps can be intrinsically smaller than in casting, but limitations arise due to strength requirements. Nevertheless, milled set rings can be produced with higher teeth than if they are cast. The high manufacture costs of milling, though, are disadvantageous.